How to ensure that SSH is configured on the new node

Posted on 2013-05-16
Last Modified: 2013-05-29
Dear experts here:

I am going to add a new node to the oracle cluster. On this document:

step 4, it asked me to "Ensure that SSH is configured on the node". Then I use root account to ssh to the new node(poseidon) from an existing node(elysium). However, it gives me the following error. When I switch to "mis" user, I can SSH in without any problem. Could anybody help me to verify if the SSH is configured well. thank you.  

[root@elysium ~]# ssh poseidon
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending key in /root/.ssh/known_hosts:3
RSA host key for poseidon has changed and you have requested strict checking.
Host key verification failed.
[root@elysium ~]#


[mis@elysium ~]$ ssh poseidon
mis@poseidon's password:
Last login: Thu May 16 15:22:32 2013 from
[mis@poseidon ~]$
Question by:Jason Yu
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LVL 21

Accepted Solution

Mazdajai earned 250 total points
ID: 39173235
Is it a reinstall or has the ip changed? If it is the case, remove line 3 on the file.

vi /root/.ssh/known_hosts

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LVL 29

Assisted Solution

serialband earned 250 total points
ID: 39173519
sed -i '3d' ~/.ssh/know_hosts

Author Comment

by:Jason Yu
ID: 39182823
After I delete the third line in this file, it works now.

Connection to poseidon closed.
[root@elysium ~]# ssh poseidon
root@poseidon's password:
Last login: Mon May 20 15:27:05 2013 from
[root@poseidon ~]#

One more question, if I want to disregard the password (so I don't need to input password every time) which should I do?

Also, how to set up log in welcome logo. thank you.
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LVL 21

Assisted Solution

Mazdajai earned 250 total points
ID: 39182828
What type of distro? You need to setup key pair for passwordless login -

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Not sure what you mean by "log in welcome logo"?
LVL 29

Assisted Solution

serialband earned 250 total points
ID: 39183369
Maybe you mean /etc/motd.  Put your text Message of the Day in the file and whenever you log in, it will be displayed.

Author Closing Comment

by:Jason Yu
ID: 39206339
thank you guys, got it solved satisfied.

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